Method and apparatus for conditioning air



Jan. 7, 1936. C R, [,WNS 2,026,936

METHOD AND APPARATUS FOR CONDTIONING AIR Filed May 23, 1936 2 sheets-sheet 1 75's ATTORNEYS Jan. 7, 1936. 1 I c. R. DOWNS 2,026,936

METHOD AND APPARATUS FOR CONDITIONING AIR Filed May 23, 1933 2 Sheets-Sheet 2 lNvENToR Zar/e5 7?. Eon/ms ATTORN EY5 Patented Jan, 7, 1936" UNITED ISTATES PATENT OFFICE ME'rnon .AND APPARATUS Fon oormr- 'Home Am a Charles R. Downs, Old Greenwich, Conn., as-

signor to Weiss and Downs, Inc., New N. Y., a corporation ofllew Yon-kdd, f

York,

'Application May 23,1933; marmi. 612.415

29 claims.

This 4invention relates to improvements in the art of controlling the moisture content of@ air or gases in enclosed spaces. O ne object of my invention is to provide an improved method and improved apparatus-to reduce .the moisture content of air N#when this' is too high to satisfy the requirements of comfort for living beings in en-l closed spaces or the requirements of proper manperature reduction.y Another object of my invention is to provide an apparatus which in addition to performing the above functions will also humidify air when this is required. Such humidificatifon'is normally dey sirable during the cold winter months.

By my process and apparatus, I am able to de- A humidify air at a temperature considerably above its dew point. This I accomplish 'by employing ai deliquescent solid and its Water solution ina novel manner." Equipment for this purpose, accord ing to'my invention, is cheaper to install and operate than when moisture is removed from air by cooling it below'its dewpoint.

which I employ comprises passing the air through a series of drying Zones which include a drying zone, or predrying step, wherein the deliquescent Amaterial is in its liquid phase, and a plurality of drying zones vwherein the deliquescent material is in its solid phase. The air during itsa passage throughv this series of drying zones is cooled in ord'erto remove the heat developed by the absorption of the moisture by the deliquescent ma- "aerial,A and the cooling isfcarried out in a plurality of stepsso that the cooling of the air will prevent thev temperature of the deliquescent mail terial inthe respective drying zonesv from ris\ ing to a point where moisture absorption frontn the air would be retarded to an impracticable extent.

According to one manner in which this meth- A od of air dehumidification may be carried-out,

the deliquesccnit solid, preferably calcium chloride, is supported in a plurality of separate masses Aor beds above aa 'series of traysv "superposecl-one. above thejother in cascade relation. The air toY be dried is directed over the surfaces of pools of `the drying liquid which are maintained on these trays, and' thenceinto`successive contact with the separate masses of the solid drying ma- According to my inven-` tion, the' airmay begdehumidied without temj cous and at the saine time possesses 'a lower vaterial and the cooling means associated therewith. The solution is drained from each of the several beds of solid deliquescent material onto the" uppermost tray, and after the solution has passed down-through the series of trays and b- 5 comes diluted to such an extent that it will ab-A sorb substantially no further moisture, it is dis? charged to waste. v

` I have found by actual practice that upon long continued gperation a tough foam blanket .tends 10 to' form on the surfaces of the unsaturated vsolutions of calcium chloride comprising the pools.` This gradually reduces the emciency ofomoisture v absorption in the predrying step or zone. Fur- 'thermoraand morepimportant, is. the fact that l5 dust in being \quantitatively removed `from the air both by contact with the pools of calcium chloride solutionand with the saturated, viscous solutions of calcium chloride on the surfaces of l the solid calcium chloride, collects as a sludge 20 'I inthese pools and makes necessary intermittent cleaning. 1

'These objectionable features I have eliminated by articially causing theA calcium chloride soy lution to be agitated and made to ow through 25 the pools ai? a rate that `Will keep them clear of foam blankets and sludge. To accomplish this,

, i I may use a pump,'whose function is/completely Briey the general method of dehumidication describedbelow, to 'recirculate the solution in the predrying step. It will'be understood that with- 30 -out this recirculation the velocity .of flow of the solution through the pools on the respective trays is governed by the rate of moisture absorbed from 4the air, and consequently is extremely low.

since by ydoing so the top pool is made more vispor pressure than-the pools below. 'In this way. in the predrying stepvthe air progressively con'-y tacts with solutions o fincreasing dust and moisture removing properties.`v 4-5 Since I have cooled the air by. contact with the cooled recirculated liquid, I may eliminate other' l air cooling or heat removing means before vthe firstv compa ent, or bed oi?- solid calcium chloride and substitute therefor a retaining screen. 50

By vrecirculating a ,relatively large volume of' cooled calcium chloride solution in ,thek predrying step, I form a. curtain or cascade of the same as it discharges overthe lips of the trays in flow- Aing from tray to tray. This flow of solution may-55 be subdivided into a multiplicity of small streams by suitable means and in so doing, I greatly increase the efiiciency of contact between the air to be dried and the calcium chloride solution. This increased contact area is not merely the larea of the liquid cascade itself but due to the high speed of air through the apparatus liquid is entrained and is thrown against the vertical walls of the predrying section of the apparatus ing a modified form of apparatus.

as well as the lower surfaces of the trays. This more than doubles the wetted surfaces of the apparatus. All of this is accomplished without increasing the resistance to airflow through the apparatus to any appreciable degree which is or great importance from the standpoint of blower capacity.

By using this improvement in the predrying step in combination with the masses of solid calcium chloride in the final drying step or zone, a process of practical utility is presented in that any entrainment of unsaturated solution is separated from the air stream in passing through the mass of solid calcium chloride and prevented from being carried out of the apparatus suspended in the air stream. 'I 'he very high viscosity of the saturated solution on the surfaces of the calcium chloride masses apparently prevents entrainment as tests made upon the air discharged from the apparatus show no chloride content.

This improvement in process and apparatus for dehumidifying air moreover provides an improved structure and process for humidifying air. In this event, the pump provided for-recirculating calcium chloride solution is used to recirculat-e heated water over the trays en cascade. The cooling means for cooling the recirculated calcium chloride solution during the dehumidication of air then becomes a heating means for heating the recirculated water for the humidiiication of air. This improvement moreover is more economical as only a very small part of the water fed to the apparatus for humidifying the air is wasted to the sewer, the volume so wasted being only suillcient to keep in solution the salts normally present in water and thereby prevent them from separating out on the surfaces of the heating means. Furthermore, the process and apparatus which I disclose herein is especially suitable for humidifying air in that it automatically heats air yafter it is humidified to a temperature that is always considerably above that of the air immediately after humidication.

Additional features of my invention will be apparent from a consideration of the accompanying drawings, in which two forms of apparatus for carrying out theinvention are illustrated, and from consideration of the following detailed description of the invention in connection with these drawings.

appended claims.

In these drawings:

Fig. 1 is a vertical longitudinal section of one form of air conditioning apparatus of my invention.

Fig. 2 is a transverse vertical section taken along line 2-2 of Fig. 1. f

Fig. 3 is a longitudinal vertical section show- Fig. 4 is a longitudinal vertical section showing anothe.` modified form'of apparatus.

Referring now to the accompanying drawings,

and rst to Figs. 1 and 2, the form of apparatus here shown forcarrying out the method of my invention comprises a housing I forming therein It will be understood howeverthat the scope of my inventionis defined in the' `waste liquid from the `reservoir I6.

an air treating chamber. This housing is made in three superimposed sections. a predrying or tray section 2, a compartment section 3 and a bin section 4. These sections are made of sheet metal bound at the corners with suitable steel shapes 5 to give stiffness. At the meeting edges of sections 2 and 3 and likewise 3 and 4, they are provided with angle bars having apertures for the reception of bolts 5 and 6 respectively by means of which the sections are secured together.

By making the housing I in these sections it may be dismantled and carried through existing doorways even for apparatus of large capacity. Furthermore, this permits the compartment section 3 to be reversed end for end upon the pre- 15 drying section 2 which may be of advantage in installing the treating chamber in a selected space. Moreover, where variations in calcium chloride storage capacity are desirable, higher or lower` bin sections 4 may be bolted to the compartment 20 section 3. The air inlet 'I into the space 8 receives air from an air distributing box 9 which extends horizontally along the wall of section 2. The air outlet from housing I is shown at I0.

The liquid holding trays II are sealed in any 25 convenient manner to the vertical walls of the section 2 along three edges and alternate trays are spaced from a fourth vertical wall by staggered passages to cause the air to flow in a zigzag fashion back and forth laterally across alternate trays during its progress up through the stack of trays in the direction of the arrows in Fig. 2. The trays II are provided at the edges adjacent these air passages with lips I2 to retain a pool of liquid on each tray and to reinforce the edgesto prevent sagging. The space 8 below the lowermost tray serves to collect the liquid as it leaves the lowermost tray and also as a space for receiving the incoming air. The floor I5 is sealed to all four walls of section 2 and is provided with a drainage opening I3 through which liquid is discharged from space 8. This opening is surrounded by a lip I4 for maintaining a pool of liquid on the floor I5.

In the 4installation of the apparatus, the housing I should be positioned in such a manner that the liquid holding trays, as well as the floor I5 of the housing, are horizontal. Thus the liquid will be maintained on these trays at a uniform depth and filling of the trays to capacity 50 may be effected. In this manner the abs'orptive power of the liquid will be utilized to a greater extent and none of the same will be carried to the discharge prematurely.

Drainage opening I3 communicates with a liq- 5; uid reservoir I6 in which is immersed a heat exchanger or cooler I1 of any suitable `construction. An overflow pipe I8 is provided which may be connected with the sewer for discharge of 'I'he heat transferring coil I1 is provided with an inlet I9 and an outlet |91. A pump 20 driven by motor 2| has its suction pipe 22 immersedin the liquid reservoir I6 below the level of the overflow pipe I8 and its discharge pipe 23 is connected through the wall lofsection 2 above the top tray II. A branch pipe 24 is provided'so that a part or all of the liquid discharged by the pump 20 may be carried from the system'by adjusting the threeway cock 25. 70

When the air has passed over the trays II as described above, and reaches the space above the topmost tray its direction of flow is changed from cross-wise ow to lengthwise flow and to do this the compartment section is provided with a gressively lower average temperatures.

bottom plate 28 which completely covers the bottom of section 3 aside from the air passageway 21. The air is caused by this plate to'flow`v towards this air passageway and is discharged into the compartment section 3 through` this passageway.

In the compartment section 3 there are provided three compartments 28, 29 and 30 of progressively increasing linear dimensionseach to contain a bed or mass of solid calcium chloride when the apparatus is operating as a dehumidifying unit. A screen 3I is provided to support the leading face of the mass of solid calcium chloride resting in the -first 'compartment 28. There are also provided two heat exchangers vor air coolers 32 and 33 which also separate the compartments 28, 29and 30. t

'I'he air entering compartment section 3 through passageway 21 passes successively through the screen 3|the solid vcalcium chloride in compartment 28, the cooler 32, the solid calcium chloride in compartment 29, the cooler 33, the solid calcium chloride in compartment 3U and the screen 34, and leaves the apparatus'through the ,outlet duct I0. The heat exchangers 32 and- 33 may conveniently be-madeof nned tubing. 'Ihese heat exchangers, when .the apparatus is used as a dehumidifying unit, are for thel purpose of cooling the air passing through them to remove the latent heat;I of condensation of moisture removed from the air together with the heat of solution of the calcium chloride to=thereby control the temperature of the respective masses, of solid calcium chloride in compartments 29 and The successful and economical reduction of humidity throughout an enclosed space such as a dwelling house depends upon producing acomparatively small quantity of air having as low-a relative humidity as possible, in order to, avoid the necessity of circulating through the dehumidifying apparatus an undulyl large volume of air. In accordance with one of the features of mypresent invention the production of air having the desired low humidity is aided by maintaining the nal bed or mass of deliquescent solid through which the air passes, that is,V bed 39, at an average temperature which is lower than the average temperature of the preceding bed, that is, bed 29. In fact it is desirable though .not necessary, to maintain the several beds or massesof deliquescent solid 28, 29 and 30 at pro- It is moreover desirable to maintain the temperatures of all of thev drying zones as low as practicable, and this is especially true of the liquid phase drying zone, since by-so doing the liquid discharged to waste through overow outlet I8 is at maxi- (mum dilution, or in other words contains Ia minimum offthe deliquesced solid. y With these'considerationsin mind, heat exchangers 32"and 33 may be connected in parallel tothe source of cooling water or otherv fluid y which is `used for cooling them,'and the rate of now of such cooling iluid adjusted toallow the several masses or beds of deliquescent solid to"- v.assume during operation ofthe apparatus the desired relative temperature. It will be under-1 Astood that thermostatic controloi:` l'this flow of the coolingi'luid may be employed if desired;

--Preferably,.h0wever, the heat. exchangers- 32 and 33 are so connected that the coolingwater ows through them in series, the waterilrst ilow- -ingthrough heat exchanger 33 and then through' 32.l This permits efticient utilization ofltlhe cooling water and assists in controlling the temperature of the mass of calcium chloride in compartment 30 at la lower point than that in compartment 29. If a larger number ofcompartments are to be used in series, I prefer connecting the heat exchangers associated with such a Vseries in the above manner so that the cooling water flowing therethrough will aid in producing progressively lower temperatures in the masses of calcium chloride in the consecutive compartments and the effect of this is to approach the minimum possible quantity of moisture in the air before it is discharged from the outlet I0.

, The heat exchangers 32 and 33 as aboveconexchanger 32. hIt will be understood that thel cooling water enters the heat exchanger system by means of pipe I9 and leaves by outlet 35 of heat exchanger 32 `from which it is discharged to waste or for yfurther use.- I

The bottom plate 29 of compartment section 3 t forms a collector` plate for receiving the concentrated calcium chloridey solution which drips from the masses of solid calcium chloride in the compartments 28, 29 vand 38 and this plate is provided with small perforations 3B to drain the solution to the body of liquid recirculated by pump 20. These several solutions are each saturated so that a sligl'it reduction in temperature Jwould cause lthem to resolidify. Such reduction in temperature is avoided, however, since the solutions are drained directly and separately onto the uppermost tray Il. 'I'he solutions are thusprevented from coming in contact with the heat exchangers 32( :and 3 3', and by discharging the solutions through the orifices 38 there is no opportunity for` cooling to occur.

" The solid calcium chloride shown in the com partments 28, 29 and 30 is in lumpjbriquet or generally spheroidal form andas these frag; ments liquefy andare reduced in size, the mass settles and contracts in volume. The bins 31, 38 and 39of bin section 4 serve to automatically replenish the calcium chloride mass vin the compartments. The bins are divided from each other within the bin section 4 b y thel division walls 49 and 4I By slanting these walls I provide storage for fresh calcium chloride lumps in bins 31,

. 38 and 39 approximating the rate at which the calcium1chloride liquees in the compartments 28, 29 and 30,' These'diyisionwalls 40 and 4I v may be -in a fixed position or vmay be attached to the tops of the radiators '32' and 33 by'hiages y with their upperedges free to be moved longitudinally to vary the ratio of these volumes. For

this'purpose, sliding plates 42 and 43 are provided so that by adjustment of the top edges of the division walls theymay bemade to fit snugly against. the under side of the cover 44 to prevent yair from lay-passing [the heat exchangers 32 and slantlng metal sheets 4.5 and 46 are pro- 4:ments 28 and- 30 but it is to be understood that these or similar sheets may be adjustable like the division walls 4I) and 4I if desired.V The'cover 44 vided tofca'use the masses of solid calcium chloride in the 'bins adjacent thereto to feed into compart- In Figures 1 and 2 the slantng walls of-the bins are shown in a slanting position longitudinally of the apparatus. It is to be understood however that they may also be slanted transversely to provide a still greater capacity for a given height.

As the masses in the compartments following the coolers shrink in volume, solid calcium chloride automatically nfeeds down from the storage bins to keep these compartments full, thereby preventing air from by-passing the masses and at the same time utilizing the maximum efliciency of the heat exchanger surfaces at all times. The bins in themselves are highly advantageous in that they may be made of lsuillcient size to hold enough solid calcium chloride to last for considerable periods of time thereby permitting intrequent servicing of the apparatus.

Furthermore, the solid calcium chloride contained in a series of compartments liquefies most rapidly in the first compartment and progressively more slowly in the compartments following in the series. By the provision of storage bins, this unequal rate of -use is compensated for by constructing the bins with Varying volumes to suit the rates at which the calcium chloride is liqueed. For example, under certain circumstances with compartments of equal length, the ratio of the rate of liquefaction of the solid calcium chloride in the compartments where there are three in series may be, for example, 50%, 30% and of the total solid calcium chloride therein. If the compartments are of the same horizontal cross sectional dimensions and the bin walls are vertical and in line with the sides of the compartments, the bin capacities should have relative volumes of 5, 3, and 2 if the bins are to be recharged with calcium chloride over the same time intervals. This makes the ilrst bin in the series unduly high since the amount to be charged ing unduly increased. This diiculty is overcome by slanting the bin walls at suitable angles to adjust the volumes to correspond more exactly with the rate at which the calcium chloride liquees in -the compartments. By this means, the distance to which the calcium chloride has to be lifted during charging is reduced and this constitutes an improvement except in cases where it may beldesirable to charge the calcium chloride from an upper floor.

In addition to the above considerations, there is another reason why the compartments should be constructed with progressively increasing length, and the bins made with progressively decreasing capacity. If the calcium chloride in the compartments liquefies at the above rate, for example 5, 3 and 2, and the compartments are all of equal length the compartment spaces are not all being eiiciently utilized. For example, if the first compartment, which receives air containing the greatest content of water, is too long, the air passing therethrough becomes heated to such an extent during the removal of moisture in the front portion of .the calcium chloride bed that substantially no moisture will be removed in the latter portion. Consequently very little calcium chloride will be liquefied in this latter portion and this represents wasted volume. On the other hand in the second compartment, the air received has a lesser moisture content and neither the bed nor the air inthe second compartment will be heated to such an extent as in the rst compartment, so thatvthe second compartment remains operative over a greater space, and consequently a smaller portion of the volumel of calcium chloride therein is ineifective. The same thing is true of the third compartment. The third compartment has still less moisture to remove and none of the calcium chloride is ineffective. If the compartments are Imade with lengths of 2, 3 and 5, I still obtain liquefaction rates of 5, 3 and 2 but I obtain a lower exit air relative humidity from the third compartment than when the compartments under the same operating conditions are of equal length.

Thisincreased efilciency in the same total contact length is probably due to the fact that I have eliminated useless bulk of calcium chloride earlier in the series and provided an increased bulk in the last compartment where it is available for 20 a ilnal clean-up of the moisture. I therefore havelsucceeded in producing a higher rate of moisture removal and a lowered moisture content of the exit air with a given volume ,of calcium chloride, constituting a great advantage in procbut are given merely as illustrative of the principle involved.

When the apparatus shown in Figs. 1 and 2 is used for humidifying air, as for example in the winter time, the masses of calcium chloride lumps are removed and the calcium chloride solutions are ilushed out of the system and discharged by means of the pump 20 to the sewer. Water is then added to the system to ll the trays Il and the reservoir Ii up to the overflow il. Steam or preferably hot water from a heater (not shown) is circulated through radiators 33, 32 and i1 in this order, and the hot water preferably permitted to return to the heater. The humidifying water heated by exchanger I1, is recirculated over the trays Il by means of pump 20 and humidiies the air passing in contact with this water. The humidifled air then passes in series through the heat exchangers 32 and I3 whereby it is always superheated and its relative humidity greatly reduced. 'This is advantageous in that the air so heated is less likely to condense out free moisture when it emerges from the outlet I0 and mixes with colder air or strikes cold surfaces. Water is added in a small continuous stream to the recirculated humidifying water by means of a pipe 48 connected to the water supply so that at all times there will be a small excess of water'overowing at Il so that the salts normally present in city water are held in solution and discharged to waste rather than separating out as scale upon the heating surfaces of radiator i1. II he heating water to be passed internally through the rai diator i1 is of such a character that a deposit be supersaturated by the entrainment of droplets in the air stream. When air of this composition s,

is dischargedthrough ducts, condensation and' steam boiler, or a hot water house heater, or from a water heating coll in a warm air furnace, rst through the heat exchangers 33 and 32 and then through the means for heating the recirculated humidifylngwater, that is heat exchanger I1. In this way the hot water is lowered in temperature `during its passage through the vheat exchangers 33 and 32,' thereby positively preventing theair during the humidifying step from being as hot as the air passing through these heatv exchangers. In most installations, I may rely upon the thermal circulation of this hot water but if the stream is too sluggishor the apparatus at -an improper level, I may correct this by means of a small circulating pump. Y

This provision for using hot water makes my apparatus adaptable as an accessory of any common central house heating equipment. For example, it provides for dependable and controllable I' air humidication even with an oil burning steam boiler wherein steam is generatedv only 'when heating is lcalled for by a thermostat.. Ii. steam is depended upon for heating humidifying water with such a boiler, it will-be heated only when steam is being generated. If the water in such held always above a minimum by an aquastat and the humidiiier be supplied with heating water at a desirable temperature at all times.

The .use of a pump for recirculating cooled calcium chloride solution in the predrying stepwhile drying air and for recirculating hot water for moistening air onstituteslan improvementfrom another standp.oint. vHouses are frequently suppliedwith sewer connections above the cellar oor level and in such cases the apparatus would have to be raised .above thel sewer connection so that the spent calcium chloride solution or the waste 'water could be discharged by gravity thereto.` By providing a pump for recirculation, I am also 1 able to dschargethese liquids to section has its air passageway 21a across the center of its length rather than across the left hand end as shown inFig. 1. The predried air passes through this passageway and splits into twopor tions to pass in a right and left hand direction'. The air stream to the leftpasses lthrough a screen 31a and `thence in sequence through com partments 28a, 29a, and 30a, the heat exohangers 32a and 33a and the screen 34a to the air outlet Illa. Similarly the air stream to the right passes through screen 3Ib, then throughA 28h, -32b .296, 33h, .30h and 34Uto outlet lb'.' The disjchargcd air may be delivered from. outlets 10a a boiler is used instead, its temperature may be and Ib to various pants of the space to be condtioned or may be4 joined together in a single discharge duct outside the apparatus. -The bins 31a, 38a and 39a and 38h and 3917 may beconstructed'on a principle similar to the bins in Fig. 1. The rest of the parts of lthe apparatus'are numbered the same as those shown in Figs. 1 and 24 and have the same functions.

Referring now to-Fig. 4 ofthe accompanying drawings, I show another forml of apparatus Qwhose parts are identical with those in Figs. 1

and 2 except that the section-containing the trays is a chamber A separate from the chamber B containing the iive compartments`28c, 29e, 30C, 30d and 30e, and bins3'lc, 38c,-39c, 39d and 39e. This arrangement has certain advantages especially in the construction of large .equipment for treating air for industrial purposes. By this division into two chambers an intermediate fan 49 in series between the chambers may be used to produce the air ilow. A

In thisevent the fan 49 draws air from chamber A and discharges it through duct 50 into chamber B' as indicated. The pump 20 discharges the circulating liquidto the top tray in lchamber A and the liquid after being cooled by the heat exchanger I1 returns by gravity to the bottom of chamberB through pipe 5| where it mixes with the liquid vdraining from the compartments in chamber B and is again drawn to the pump through pipe 22. By means-'of liquid recirculation, this type of structure is madeopera-A tive. I moreover show -at 52 a heat exchanger in the inlet duct 9 whereby the air may be heated or cooled before coming into contact `with the recirculating liquid in chamber A.

In this rotin of the invention, the tendency of th'e calcium chloride to. cake and clog .in and around the outlets 36` in the bottom of the screenlike support 26a, upon which the calcium chloride rests. is materially lessened. This tendency of the concentrated material to cool and resolidify in outlets 36 is lessened since the air issuing from the duct is conned to contact with the solid material and does not pass directly abovethe sur-` face of the solution lin the bottom of the chamb er B. Also 'because the-concentrated solution which drips through' the apertlu'es 36 is dropped .into and washed by the dilute solution issuing from the reservoir in the chamber A, there is no opportunity for resolidicatlon due to cooling of the supersaturated solution below the tempera-i ture at 4which it solidies. c;

tus is operating as av dehumidier in summer, solid calcium chloride is contained in compartments 28c, 29c, 30e, 30d andv 30e and calcium chloride solutionis recirculated by. pump '20.

- During this operation it may be advantageous to cool the incoming air below the` atmospheric It is to be understood thatwhen the appara- '55 temperature by means ofthe heat exchanger 52. v

Moreover, when operating in Iwinter as a humidii lier the compartments 28e, 29e, 30c, 30d and :ille

the atmospheric temperature by means of the heat exchanger 52. This heat exchanger may be heated or `cooled by passing therethrough any convenient'uid of the proper temperature to ob. *Y

tain the results desired.

4It will be understood that with all these forms of apparatus, automatic controlo! the conditioned air kin the house space may be provided by employing available control accessories such as humidostats, aquastats, and thermostats to actuate various parts of the apparatus. Other variations of the apparatus can be provided to meet the limitations of a specific set of conditions. Control can be manual or automatic in all forms of equipment for both winter and summer. The specific examples described are merely illustrations and I do not intend them to limit the scope of my invention.

By the term calcium chloride, as used in the appended claims, I intend to include either anhydrous' calcium chloride or other solid varieties of calcium chloride containing water of crystallization. For general use I prefer solid calcium chloride containing about 25% of water of crystallization.

This application is a continuation in part of my copending application S. N. 629,121 filed August 17, 1932.

I claim- 1. The method of dehumidifying air by the deliquescence of a solid deliquescent material which comprises passing the air through a series of drying zones including a liquid phase drying zone and plurality of solid phase drying zones, cooling the air during its passage through said liquid phase drying zone, cooling the air between each of said solid phase drying zones, and draining the solutions from said respective solid phase .drying zones independently of one another.

2. The method of dehumidifying air by the deliquescence of a solid deliquescenfmaterial which comprises passing the air through a series of drying zones including a liquid phase drying zone and plurality of solid phase drying zones, removing heat from the air during its passage through said liquid phase drying zone, cooling the air between each of said solid phase drying zones, and draining the solutions from said respective solid phase drying zones independently of one another, and transferring lthe same to said liquid phase drying zone.

3. The method of dehumidifying a gas which comprises recirculating a solution of a deliquescent solid, cooling said recirculating solution, passing the gas in contact with and counter-current to the fiow of said recirculating solution, then passing the gas through a series of bedsof said deliquescent solid, cooling the gas between said beds, collecting the solutions draining from said beds and transferring them to the body of said recirculating solution without allowzontally through a series of beds of solid calcium comprising means for supporting a plurality of separate masses of solid material, a plurality of trays forsupporting pools of liquid such material arranged in series, means for directing the air to be dried over the surfaces of said pools `compartments and adapted to cool the air as fand then into successive contact with said separa'te masses, means for removing heat from the air .while it is in contact with said liquid, a heat exchanger positioned in the air stream adjacent each of a plurality of said masses for controlling 5 n the temperature of said masses, and means for draining the solution from said masses and transferring the same to said trays without contact with said heat exchangers.

6. An apparatus for dehumidifying air by the l0 deliquescence of calcium chloride or the like comprising means for supporting a plurality of separate masses of solid such material, a plurality of trays for supporting a plurality of pools of liquid such material arranged in series, means 15 for directing the air to be dried over the surfaces of said pools and then into successive contact with said separate masses, means for removing heat frorn the air while it is in contact with said liquid, a heat exchanger positioned 20 in the air stream adjacent each of a plurality of said masses and controlling the temperature of said masses, said supporting means for said masses being arranged horizontally over the uppermost of said trays, and means for separate- 25 ly discharging the solution from said respective masses onto said uppermost tray.

f '7: An apparatus for dehumidifying air by the deliquescence of calcium chloride or the like comprising means for supporting a plurality of 30 separate masses of such solid material, a plurality of trays for supporting a plurality of pools of such liquid material arranged in series, means for directing the air to be dried over the surfaces of said pools and then into successive contact with said separate masses, means for removing heat fromv the air before it traverses each of said masses, and means for draining the solution from said masses and transferring the same to'said trays, said supporting means for the sep- 40 arate masses of solid material being of progressively increasing length and serving to support masses of progressively greater'length in the direction of air travel through the same. r

8. An apparatus for dehumidifying air by the 4" deliquescence of calcium chloride or the like comprising a plurality of compartments arranged side by side to receive solid such material in lump form, means for directing air to be dried horizontally through said compartments in series, means for draining from said compartments the solution which forms on the solid material therein, heat exchangers separating a plurality of said wardly from the top of each of said heat exchangers to the top of said storage chamber.

9. An apparatus for dehumidifying air by the g5 deliquescence of calcium chloride or the like comprising a plurality of compartments arranged lside by side to receive solid such material in lump form, means for directing air to be dried horizontally through said compartments in series, 70 means for draining from said Acompartments the solution which forms on the solid material therein, heat exchangers separating a plurality of said compartments and adapted to cool the air as it enters the compartments, a single storage `aoaaese chamber for the lump material above said com- V partments, and means for dividing said chamber into hopper sections.

10. In an apparatus of the character described, lthe combination of a chamber containing a plurality of vertically spaced horizontal trays, means "for circulating cooled calcium chloride solution in aclosed circuit over said vertically spaced horizontal trays, a series of compartments to hold solid calcium chloride, a cooler betweenl each t'wo successive-,compartments inthe series, means for discharging calcium chloride solution from the compartments to the circuit oi circulating solution without allowing the solution from any one compartment to contact vwith the solid calcium chloridein any other compartment, and

.trays means for 'circulating calcium chloride vsolution in a closed circuit `in contact with a cooling means, thence to the top tray of said plurality of vertically 'spaced horizontal trays, thence dowl in cascade from tray to tray and thence i'nto contact with said cooling means, a

series of compartments to contain solid calcium chloride, a cooler between each two successive compartments in the series, means for discharging calcium chloride solution from each compartf ment to the circuit of circulating solution withv out allowing the solution from any one `compartment to contact with the solid calcium chloride in any other compartment,=means for removing excess solution from said closed circuit, 'and means for directing the passage of air successively over the trays in said chambercountercurrent to the circulating calciuni chloride solution and horizontally through the said compartments and coolers.

12. In an apparatus oi the 'character described, the combination of a chambercontaining a plurality of vertically spaced horizontal f trays, means for circulating calcium chloride` solution in a closed circuit in contact with a cooling means, thence to the series oi said vertically spaced trays, thence down in cascade from tray to trayand thence into contact with said cooling means, a series of compartments to contain lumps of solid calcium chloride, means for conveying calcium chloride solution from saidL compartments to the circuit of circulating solution, a cooler between each two successive compart-ments, a bin arranged above each vcompartment to. keep it full of calcium chloride lumps, and means for directing a current of air successively over the trays in s aid chamber and horizontally through said 'compartments and coolers. f e

directing. a current of air successively over the shelves in said chamber counter-current to the iio'w of, said calcium chloride. solution and through said series of compartments andl coolers.

14. In an apparatus of the character described, the combination oa chamber containlng a plurality of staggered vertically spaced shelves, a series .of compartments to contain lumps of solid calcium chloride, each of said compartments in the series being longer than 10 the one immediately preceding it, a cooler between each two successive'compartments, a bin series relationship.

above each compartment arranged to keep it Afull of calcium chloride lumps as liquefaction proceeds, the size of said bins decreasing so as 15 to vary in approximate proportion to the liquefactlon occurringin the compartments which they feed, means for discharging calciumchloride solutions from said compartments to said shelves, and means for directing a current of 20 air successively over the shelves in said cham-- .i ber counter-current to the ow of said solution andthrough said series of compartments and coolers.

` 15. In an apparatus of the scribed, an enclosure with inlet andv outlet' for f conilning a stream of air, a series' of compart- Q!nents within said enclosure for supporting lumps lof solid calcium chloride, each of, said compartments in the series beingl longer than the. one 30 immediately preceding it, a coc-ler between each two successive compartments, and means for forcing airr through s aid enclosure anda1ter nately through the compartments and coolers in 35 16. In an apparatus of the character described, an enclosure with inlet and outlet for confining a stream of air, a series of compartments within said enclosure -for supporting lumps of solid calcium chloride, each of said Vcompart- 40 ments in the series being longer than the one immediately preceding it, a bin above each comchloride lumps as liquefaction proceeds, the second of said bins in the series beingl smallerA than 45` the compartments and Vcoolers in series relation-'- 13. In an apparatus of the character de scribed, the combination of a chamber containing a`plurality of vertically spaced horizontal shelves, a series of compartments above said chamber to contain lumps oi'asolid calcium ,chloride, means for discharging calcium chloride solution from said compartments to said shelves,

a coolerbetween .each two successive 'compartments, a lbin above each compartment arranged te keep it-full of calcium chloride lumps, the size of the said bins varying in` approximate proportion to the liquefaction occurring in the compartments which they feed and means fory -.ship.

. 50 17. The method of dehumidifying air. which comprises-passing air through. a bed of calcium chloride whereby it is partially dehydrated and its temperature is increased, reducing the temperature of the thus partially dehydrated air to a 55 temperature as low as the temperature at which it entered the calcium chloride bed and passing the thus cooled air through a second c'alcium chloride bed of materially greater length than said first calcium chloride bed.

13,A The methodof dehumidifying air which' comprises passing the air through a bed of lump calcium chloride whereby part of vits moisture is removed and its temperature increased, cooling the thus partially dehumidifled air 'to partially 55 restore its relative -humidity without addingn moisture-,theretm and passing the said cooled air through va second bed' of .lump calcium chloride to remove further moisturev therefrom, while at the same time drainingv the solutions resulting from the deliquescence-of each bed without contact with the other bed or with the drainage from another bed.

19. In an apparatus for dehumidifying air by the deliquescence of calcium'chloride, perforated 75' character de- 25` partment arranged to keep it iull lof calcium .Y

supports arranged in a single horizontal plane, beds of calcium chloride carried thereby, means for maintaining a dilute solution of calcium chloride beneath each of said supports in close proximity thereto for collecting the concentrated solution dripping through said supports from each of said beds, means for continuously circulating said dilute solution beneath each of said beds and in direct contact with=the air to be dehumidied, and means for conducting the air through said beds after such direct contact.

20. The method of dehumidifying air which comprises passing partially dehumidied air through lump calcium chloride in the form of a bed, whereby part of its moisture is removed and its temperature-increased, maintaining the volurne of the bed constant, cooling the thus dehumidied air to partially restore its relative humidity and passing said cooled air through a second similar bed of lump calcium chloride to remove further moisture therefrom and utilizing the solutions resulting from the deliquescence of said beds for the initial partial dehumidication of the air passed to the rst bed.

21. The method of dehumidifying a gas which comprises passing a partially dehumidied gas through a cooled bed of deliquescent solid lumps, catching the concentrated solution thereof which drips from the bed in a dilute solution of the deliquescent material which is not in contact with the gas and then circulating` the resultant solution in contact with the gas to partially dehumidify it.

22. In an air conditioning apparatus which employs a cooled bed 'of solid lump deliquescent material .through which air is passed for dehumidication thereof, the method of preventing resolidification of -the concentrated solution which is formed in and drips from the bottom of said bed which comprises continuously catching the concentrated solution in a dilute solution of the deliquescent material which is not in contact with the gas and Vcirculating the resulting solution in contact .with the air to be dehumidiiled.

23. The method of conditioning air which comprises circulating the air over pools and through cascades of liquid calcium chloride'to removey moisture and dust therefrom, circulating all said air throughA beds o( lump calcium chloride to remove moisture and substantially all dust therefrom and liquefy the solid calcium chloride, draining the dust-containing liquefied calcium chloride separately from each bed into a pool of dilute calcium chloride and circulating the liquefled c alcium chloride through all of said pools and cascades.

24. The method 'of' claim 23 in which the air is I articially cooled during its circulation through the beds of llump calcium chloride.

25. 'I'he method of vdehumidii'ying air which comprises passing all of the air which has been partially dehumidiiled through a bed of lump calcium4 chloride whereby a part of its moisture is removed and its temperature increased, cooling the thus dehumidied air to partially restore its 5 relative humidity Without adding moisture thereto and passing said cooled air through a second bed of lump calcium chloride to remove further moisture therefrom, draining the solution from one bed without contact with another bed, and l0 utilizing the solutions resulting from the deliquescence of said beds for the initial partial dehumidication of the air passed to the rst bed. 26. Inapparatus for dehumidifying air by the deliquescence of calcium chloride, the combina-k 1Q tion of a plurality of compartments containing solid Icalcium chloride and having separate and independent drains for the solution formed therein by deliquescence, a container for receiving the solution directly from the' independent drains, a 20 circulatory system comprising a plurality of trays and means for circulating calcium chloride solus tion through said container and said circulatory system and means for passing air through said circulatory system in counter current contact with 25 said solution and through said compartments.

27. In apparatus of the character described; the combination of a series of compartments for containing solid calcium chloride said compartments having drains arranged to permit calcium 30 chloride solution formed by deliquescence to flow from ea'ch compartment independently,.a circulatory system arranged to receive directly from each compartment the solution owingtherefrom and means for passing gas 'through the circulatory 85 system in counter current relation'with the solution and through the compartments.

28. The method of dehumidifying a gas whichcomprises providing beds otsolid calcium chloride of progressively greater length in the 4direction of 40 the gas flow, passing the gas through said beds, cooling the gas between said beds, draining the liquefied calcium chloridev separately from ea'ch.

'bed withoutcontact with another bed and maintaining the volume of said beds by automatically 45 rplenishing the samewith solid calcium chloride as liquefied calcium chloride is `drained therefrom. 29. The method of dehumidifying a gas which comprises providing beds of solid calcium chloride, passing the gas through said beds, cooling the gas 50 between said beds, draining the liqueed calcium chloride from said beds and maintaining the volume of said beds by automatically replenishing the same with solid calcium chloride as liqueiled calcium chloride is drained therefrom, catch- 55 ing the liqueed calcium chloride and passing 'the gas in contact therewith prior to its passage through the beds of solid calcium chloride.

CHARLES R'. DOWNS. 60 

